A feature of the Steam Generating Heavy Water Moderated Reactor is the provision of a spray cooling system on which major reliance is placed to limit fuel cladding temperatures during a loss-of-coolant accident.
LOCA-MK-2, which has been written to compute SGHWR fuel temperatures in a loss-of-coolant accident, therefore models conditions in which blowdown cooling is only of marginal interest and where the major sources of heat removal are spray mechanisms and radiation. LOCA-MK-2 models the fine details of the fuel cluster, and zircaloy oxidation and radiation.